what causes earth leakage?

[ExArmy]

testing a house today before I put RCD protection on it and i got 300mA earth leakage. appox 100mA from the sockets, 180mA on the downstairs lighting circuit, then 20 odd mA accross the rest of the circuits.

I had a poke around the downstairs lighting circuit, couldn't see anything obvious, did R2 tests at all points (OK), did IR test and it was in the region of 650MΩ L-N, L-E and N-E.

as for the sockets, 2 chest freezers that are older then me are the cause of 50mA between them, rest is unnacounted for?

what causes this?

 

[pushrod]

if its pme it may be some diverted neutral current.

Regards chris

hi chr!s, care to expand on this?

 

[topquark]

hi chr!s, care to expand on this?

That's got my curiosity too!

 

[telectrix]

think it's electron confusion as the E and N are connected together at the head, the poor little buggers don't know which route to take.

 

[topquark]

think it's electron confusion as the E and N are connected together at the head, the poor little buggers don't know which route to take.

Tel has discovered a new quantum effect: Indecisive electrons

 

[telectrix]

they were fine when they were using a map and compass, but now they've been supplied with a sat.nav. that's what's buggered the poor little sods. they want to take the neutral path, but the sat.nav. directs them down the earth path, even though it's clearly marked as " no through road for electrons".

 

[topquark]

They'll be inventing duality next so they can go both ways at the same time just to confuse us.

 

[telectrix]

the really confusing issue is when the positrons decide to intervene. a traffic jam at the junction would ensue, causing road rage and the release of megajoules of energy, this could result in a massive meltdown of the supply cable and so we could all have the rest of the day in the pub

 

[wade88]

ah but thats where the sub atomic particle police turn up and arrest all the rowdy particles and throw them in a capacity for the night until they find a use for them...

 

[telectrix]

use to be called a cell block, but now it's a custody suite with CCTV cameras in the bogs. wonder what the new name for a cess-pit is now. excrement suite? , poo parlour?

 

[Chr!s]

hi chr!s, care to expand on this?

Hi Pushrod

Well as Tel has already stated, becuae of the PME link the neutral current has a several paths, now dependent upon the CNE/PME impedance and the impedance of the protective conductors to earth, then you will find that some diverted neutral current will flow through the protective conductors.

The diverted neutral currents may be from your installation or even a neighboring installation.

Place a amp clamp around the live conductors at the origin on a TNC-S and see what leakage is present,and what the RCD will see.

Now dependent upon current, place a clamp/leakage clamp around the Earthing conductor and then other protective conductors.

See what you find

 

[topquark]

Oooh, now that's a tease. Are you suggesting that the imbalance in the live/neutral won't be reflected in the main earth for the instalation? That's nothing surprising because of the other extraneous paths, why is this more prevalent with PME? I feel like I'm missing something now

 

[telectrix]

i think the answer lies in a piece of toast. have you noticed, every time you drop a piece of toast, it always lands butter side down.

 

[kung]

650 meg is a great IR reading !

 

[telectrix]

and here was i thinking we'd got nicely off topic.

 

[topquark]

650 meg is a great IR reading !

And how many meters go that high? I suspected it was 650Ohms not MegOhms.